The range of size, shape, color, personality and purpose for which dogs are bred is jaw-dropping. Over centuries, different dogs in different geographic locations have been honed by humans to play certain roles, from hunter to guardian, from herder to companion. For some of these breeds, size has been a significant player in the search for perfection, whether that was to hunt bigger or faster game or guard a home with more intimidation, or even just to have the mass to survive in freezing locations. Of the hundreds of dog breeds around the world, here are nine of the largest.

The Great Dane is a large German breed of domestic dog known for its enormous body and great height. The German name of the breed is Deutsche Dogge, or German mastiff. The Great Dane is one of the world's tallest dog breeds. WikipediaLife span: 6 – 8 yearsOrigin: GermanyHigher classification: DogHeight: Female: 28–32 inches (71–81 cm), Male: 30–34 inches (76–86 cm)Temperament: Devoted, Reserved, Gentle, Friendly, Confident, LovingWeight: Female: 99.2–130.1 lbs (45–59 kg), Male: 119–198.4 lbs (54–90 kg)

Though they aren't the heaviest dogs, reaching around 100-120 pounds, they are among the tallest. The average Great Dane stands around 28-30 inches tall but are often taller. The world record holder for tallest dog was a Great Dane named Zeus who stood an astounding 44 inches tall. However, these big dogs trade longevity for their size, and live only to be between 6 to 8 years old. Zeus died of old age at just 5 years old.

Though the Great Dane is typically considered the largest of all dog breeds, we're going to look at a few other breeds that give this one a run for its money, including one breed that is actually even taller.

The Neapolitan Mastiff or Italian Mastiff, is a large, ancient dog breed. This massive breed is often used as a guard and defender of family and property due to their protective instincts and their fearsome appearance. WikipediaLife span: 8 – 10 yearsHigher classification: DogOrigin: ItalyTemperament: Protective, Obedient, Stubborn, Fearless, Dominant, TrainableWeight: Male: 132.3–154.3 lbs (60–70 kg), Female: 110.2–132.3 lbs (50–60 kg)Height: Male: 25–30 inches (63–77 cm), Female: 23–28 inches (58–70 cm)This breeds is known for being fearless and protective of

home and family, making them an ideal guard dog -- but not an ideal warning system. They tend to be quiet, and are known for sneaking up on intruders rather than barking to warn them off. Because of their protective nature, you certainly don't want to stand between these dogs and their family, which makes this dog a breed only for owners well versed in dog training and able to put in the extensive time needed for socialization

Going back to the leggy breeds, the Scottish deerhound gives away its purpose and origin in its name. Originating in Scotland well before recorded history, the breed is a courser, once used to hunt red deer and easily chasing down its prey. They are larger and heavier than greyhounds but are built similarly, with a lanky body meant for speed.

The Dogue de Bordeaux goes by several other names, including the Bordeaux mastiff, French mastiff or Bordeauxdog. But this breed, by any other name, still stands as massive. Though other breeds, from the poodle and French bulldog to the Great Pyranese and Basset hound may be more famous breeds of French origin, the Dogue de Bordeaux is one of the most ancient breeds of France.

Unlike the Neapolitan mastiff, the Bordeauxdog has been used for more than simply guarding house and home, though that was also in its job description. These dogs also were used for everything from watching over flocks to pulling carts. It has historically been a true working dog and a jack of all trades -- at least, as far as dogs go. The breed is active and energetic outdoors, but once inside is, well, mellow to say the least.

The Newfoundland dog is a large working dog. Newfoundland dogs can be black, brown or white and black or gray. However, in Canada, the country of their origin, the only correct colours are black or white and black. WikipediaHypoallergenic: NoLife span: 8 – 10 yearsHigher classification: DogTemperament: Gentle, Sweet-Tempered, TrainableWeight: Male: 132.3–154.3 lbs (60–70 kg), Female: 99.2–121.3 lbs (45–55 kg)Height: Male: 27–29 inches (69–74 cm), Female: 25–27 inches (63–69 cm)

The Newfoundland is a working dog from, you guessed it, Newfoundland. Unlike many larger breeds, the Newfie wasn't bred to be a guard dog. Instead, its purpose was originally to help fishermen. The big, muscular dogs are able to haul nets and lines from boats, pull carts and, most importantly, fetch anything that falls overboard, including people. The breed is an exceptional water dog and strong swimmer, and there have been many rescues of people out at sea credited to these big, gentle-natured dogs.

Their size is a significant part of the breed's past purpose, which included blood sports such as baiting bears, bulls and lions. Today, however, they are simply gentle giants, letting those courageous and fearless aspects of the breed's temperament sit on the back burner while the mellow, even-tempered and loyal sides come forward. They can make excellent family dogs as they are so easy-going. So if your kids are asking for either a dog or a pony, well... it's not like size should factor into your decision:

The St. Bernard or St Bernard is a breed of very large working dog from Swiss Alps and north Italy, originally bred for rescue. The breed has become famous through tales of alpine rescues, as well as for its enormous size. WikipediaLife span: 8 – 10 yearsMass: 140 – 260 lbsHigher classification: DogTemperament: Lively, Watchful, Gentle, Friendly, CalmHeight: Male: 28–35 inches (70–90 cm), Female: 26–31 inches (65–80 cm)Origin: Italy, Switzerland

The Saint Bernard of brandy-toting fame is a breed originally created in the Swiss Alps and northern Italy as a rescue dog. The monks of the Saint Bernard Hospice are credited with training dogs for rescue and for playing a role in developing the breed we know today. Dogs can stand between 25-30 inches tall and weigh anywhere from 140 to 180 pounds.

Though they were originally used as rescue dogs to find and save travelers, today's Saint Bernards are mostly family dogs. They are famous for being gentle, loving, friendly and great with children.

His direct ancestor is the "Canis Pugnax" (the old Roman Molossian) of which he is the light version employed in the hunting of large wild animals and also as an "auxiliary warrior" in battles.

For years he has been a precious companion of the Italic populations. Employed as property, cattle and personal guard besides being used for hunting purposes too.

In the past this breed was common all over Italy as a ample iconography and historiography testify. In the recent past he has found an excellent preservation area in Southern Italy, especially in Puglia, Lucania and Sannio.

His name derives from the Latin "Cohors" which means "Guardian,” "Protector."

Even so, history has reserved a special place for the Tibetan Mastiff. They are considered by many to be the basic stock from which most modern large working breeds, including all mastiffs and mountain dogs, have developed. Even though a great deal has been written about them since the 17th Century, there are few specific details available.